Safety device for hot-water boilers



Nov. 12, 1929. A. G. SPINNEY ET AL SAFETY DEVICE FOR now WATER BOILERS Filed April 18. 1928 2 Sheets-Sheet 1 1n venlor A lYfl/TEW G. Sew/v5 Nov. 12 1929. A. a. SPINNEY ET 'AL 1,735,415

SAFETY DEVICE FOR HOT WATER BOILERS Filed April 18. 1928 2Sheets-Sheet 2 IIIIIH" 1 Fi 'y. 6'

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Patented Nov. 12, 1929 ANDREW G. SPINNEY AND CHARLES A. TWIGG, OF'PORTLA'ND, MAINE SA'FETYVDEVICE FOR HOT-WATER BOILERS Application filed April 18,

Our invention relates to a safety appliance designed more particularly for use in connection with hot-water tanks or boilers in which water is heated for household purposes.

The primary object of our present invention is to provide facilities for automatically relieving the boiler of excess pressure or to means acting to reduce the temperature of the Water therein when either or both rise to the a point where injury to the boiler or even a disastrous explosion thereof might occur.

I Numerous devices have from time to time been proposed for this purpose, including the ordinary safety-valve, thermostatically I controlled valves, fusible plugs and various combinations thereof; i v In our safety appliance we have discarded the fusible plug as being unsatisfactory for the reason that it does not respond quickly to slight variations in temperature and have also ascertained, from long experience with these devices, that a single source of relief is not always dependable; we have therefore conceived and constructed apparatus combining the conventional type poppet valve with a novel thermostatically controlled connection therewith, the former taking care of and relieving the boilerfrom abnormal rises in pressure from any source and the latter cf ,30 fording relief from temperature increases above a safe and predetermined degree, regardless of pressure conditions. The thermostatic elements, by reason of the strength of their expansive properties, are also effective in lifting the valve when for any reason it becomes inoperable due to being stuck on its seata prolific source of explosions in hotwater boilers.

It is not now considered good practice in operating high pressure waterboilers to place reliance wholly on street mains through which to provide expansible relief from excessive or rising boiler pressures.

In cases where very little hot water is be- 'ing drawn from the boiler and the heating apparatus eeither a kitchen range or gas heater, is being overworked, the temperature of the water soon reaches a very high point. There is then a conflict between the cold water from the street main and the over- 1928. Serial No. 271,006.

heated water inthe boiler and a violent ham niering takes place, sometimes sufficient to cause leaks in the piping system or even to causea rupture in the boiler itself;

The logical {and effective method of alleviating this conditi0n,-in fact to anticipate and prevent it, is toestablish a limitin temperature above which it is not feasible to heat the water.

This desideratum is effected in our device co by means of the thermostatic control over the temperature of the boiler water brought about by the discharge of more or less of the over-heated water and the admission of cold water from and to the boiler, respectively, rec3 sulting in a normal and average temperature being maintained regardless of occasional forced operating of the heating apparatus.

The preferred method of application of our safety device provides for the inclusion 7- 0f the boileritself as one of the elements in the thermostat, and utilizing the maximum expansion of the boiler when highly heated supplies a great range in thermostatic movement,-insuring a very sensitive acting relief 7- andfpositive and quick opening valve.

WVe have illustrated our invention by the use of the accompanying drawings in which, I I a Fig. 1 is an elevation of a hot water tank with our safety device mounted thereon;

Fig. 2 is a fragmentary sectional elevation thereof, drawn to a larger scale, the section being taken on a central, vertical plane through the parts,the valve being shown in closed position; I

Fig. 8 is a sectional elevation of the safety device showing the valve in open position Fig. 4 is a fragmentary perspective view of the lower portion of the valve body and ti) the fulcrum arm integraltherewith;

Fig. 5 is a perspective view of the lifting beam, and

Fig. 6 illustrates a modified formof the device.

Like parts are identified by similar reference characters.

Referringto the drawings, 1 represents a hot-water boiler mounted on the usual supporting leg 2. The inlet pipe forcold Water supply is at 3, the service hot-water delivery pipe at a, the pipe carrying hot water from the heater at 5 and the return pipe to the heater, from the boiler, at 6the foregoing parts all being conventional construction.

Secured to the top portion of the boiler is a flanged fitting 7 directly connected to which is a nipple 8, which however, might be incorporated as an integral portion of the body or housing 9, to which, as shown; is connec ted the other end of the nipple8. I

Depending from the Side of the hoasine 9 is a f t.

laterally projeciing lugs 10"; Sea tl ese projections, 10, is the lifting beam ll, the overhanging lips 11 ofwhich directly supporting the beam, and the nipple 8 disposed Within the opening 12.

On the short levered end of the beam are bearing ledges 13 upon which rests a nut l4 adjustably secured to the rod l5wl1'ich operates throiigh the hole 16in the beam. This roe extends downwardly and is sec. red to the bracket 17 fixed on the lower end of the boiler 1. protectingand insulating sleeve 18 covers the rod 15. I @n the opposite, or long lever-ed end 01" the beam 11 rests the lower end of the valve lifting lever 19, the latter having an offset portion 20 atits top end in which is a hole 21 through which operates the valve spindle 22. A collar 23, pinned on the 'spii'idle. serves as means wherebv the lever 19 may ra the valve. 2-1 lixed on the lower end of the spindle 22. e j

The top or the housing 9 is provided with suitable spindle-packing means, the stni ingbox 25 on the u; Der end otvfhich is the o gland nut 26. A helical spring 2! acts o hold the valve ohits seat 28, against the outward pressure oit the'bo'iler water The lower end of the stulling {505; is screw t we'aded and adjustable in the housing 9, dilterent adjustments of which serving to provide dill'erent degrees of expansive power in the 'spri ""27 which is set to accommodate any particular pressure it is desired to carry in-the boiler;

An outlet )ipe29 takes a'wavanv water or steam escaping from the boiler when the valve is raised from its sen. A lock ring 30 attached to the housing by the screw 31 prevents tiiirni'ng star nut 14 afterthe correct thermostatic adjustment of the rod has beenm'ad'e. h I j j H V \Ve hev'e also disclosed in Fig. 6 a slightly modified form ofsal'e'ty device. embodying. however, the same principle as the one, the

c aracteristics of which has just been, set

icallv responsive element is the pipe '32 which serves as a substitute for the boiler as 'torth. l'n'th'is arrangement,'the'therniostatend of the boiler make circulation possible through this pipe which now serves as the expansible elementin the thermostat. It will be observed that the plug 34: used in the former application of the device is now replacec by the nipple 35 through which the hot water passes downwardly through the eipansible element 32.

The operation of the safety device is automatic after the proper adjustments are firs made. The stufling-box 25 is first adjusted with reference to the spring 27 to give the lattcr the required resistance to withstand the IJTGJbolQ to 32 carried on the boiler. The nut ii is adjusted tobring all the oints and contacting surfaces of the different parts together,such parts, for instance, as the bearing ledqeslii, lugs 10, lips 11 and the two ends of the lifting lever 19. This adjustment is properly done while the boiler is normally ed, after which the nut 14 is relaxed tly to we the proper lee 'way forfarther expansion of the boiler before the effective action of the thermostat takes place which occurs when further raising the temperature at the water causes itto function and by raising the valve 245 provide reliet'from excessive temperaire, or excess pressure *aused by increased temperature:

In reciting specifically, the actions produced in the several elenients in tlrethermostatic combinatiom'as disclosed infthe constr ction illustrated in l and 2, we will b gin with the boiler itself. I It is very unual to incorporate in this classoi' apparatus an expansible element, ot'so large proportions as is this boiler, but in this case it provides a verj effective agent for the purpose.

hen the water temperature increases sufliciently the housing 9 rises with the expansion of the boiler. lifting one end of the beam ll,theother end being restrained liy the rod 15 (see Fig. 3) which being protected from the excessive heat eivpands inappr'eci'ably. The uplift ot' the beam causes the lifting lever 19 to rise, producing a corresponding upward movement ol'the spindle 22 and valve 24:.

The alternate form of device shown in Fig.

6 oierates in principle similarly to tho'one just described. The pipe 32'is the e'rpanc'ling element. and might, moreover. be considered as a. small boiler through which the hot water circulates; the rod 15 is secured in'a manner co-ezitensi vely with the pipe 352 and resists the upward movement oi": the beam 11 when the pipe 32 expands. A I

r Furthermore, it isv obvious that the lifting 33 might be attacl'red directly to-the bottom end of the boiler Lin which case theexpansile element 32. of the same lenfgflras t'he'b'oiler, is provided with substantially the "same characteristic *0 far as expanisibi'lityis eoncerned, as obtains in the lir'ststj le of device describet. Alnd, due to the proportions of the leverage in the lifting beam andithe unusual length of expansibility in the expansive member an extremely sensitive and effective lifting action is procured with the least appreciable amount of change in temperature developing in the boiler water.

Should there, from any cause other than from increased temperature, be an increase of gauge pressure within the boiler, the valve 24 is free to act, independently of the ther mostatic action of the temperature regulating elements.

The upper chamber a in the housing 9 serves as space in which the valve and spring may operate and from the lower chamber 5 a service hot-water pipe (not shown) may extend,-the plug 34, of course, being removed.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

1. A safety device adaptable for use on hot water boilers, comprising in combination a valve housing having two chambers therein, a partition, having a valve seat thereon, interj acent said chambers, a relief valveoperable on said seat, means providing communication between the interior of the boiler and'one of said chambers, an escape pipe from the other of said chambers, yielding means acting to seat and hold said valve against the normal water pressure in the boiler, and means, thermally responsive, to open said valve against the force of said seating means when the temper ature of the water in the boiler shall have reached a predetermined degree.

2. A safety device for a hot water boiler, comprising in combination a valve housing fixed on the boiler and having therein two chambers, oneof whichbeing in c0mmunication with the interior of the boiler, a valve seat interjacent the two said chambers, a valve operable on said seat and adapted, normally, to close communication between said chambers, yielding means permitting said valve to open when the pressure in the boiler has risen above a predetermined. amount, and thermally responsive means adapted to act to raise said valve from its seat when the temperature of said boiler shall have reached a predetermined degree.

3. A safety device fora hot water'boiler, comprising in combination, a valve housing mounted on said boiler and having a chamber therein in direct communication With the interior of said boiler, said chamber having a dscharge outlet therefrom, a valve adapted to control said outlet-either to open or close the same, yielding means permitting said valve to open upon the pressure in said boiler reaching a predetermined amount, a lifting beam fulcrumed on said housing, a valve spindle, a lifting lever secured to said spindle and adaptable of actuation by one end of the said lifting beam, and means to ing beam adj ustably lifting beam,and means to fixedly secure the hold the opposite end of said lifting beam substantially immovable when said housing is raised by the expansion of said boiler in response to a rise in the temperature thereof.

4. A device of the character described 7 comprising in combination a water-holding member, a valve housing attached thereto at one end thereof, and having a chamber in direct communication with the interior of said water-holding member, a discharge outlet from said chamber, a valve adapted to control said outlet-either to open or close the same, a lifting lever operably connected to said valve, a lifting beam fulcrumed on said housing and making connection with said lifting lever, means to hold one end of said lifting beam substantially immovable while the other end is raised in response to the expansion of said water-holding member, whereby communication may be established between the interior and the outside of said water-holding member.

A device of the character described comprising in combination a water-holding member, a valve housing, having a chamber therein, secured to said member, said chamher being in direct communication with the I interior of said water-holding member and having a discharge outlet therefrom, a valve adapted to control the passage of water from said water-holding member through said outlet, expansible means acting on said valve to close said outlet, means to vary the expansible force applied to said valve to close said outlet, a valve spindle fixed on said valve, a lifting lever attached to said spindle, a liftfulcrumed on said housing and making connection at one of its ends with said lifting lever, a rod, disposed in separated relation to said water-holding member, secured to the other end of said opposite end of said rod to said water-holding member. I a p In testimony whereof we affix our signatures.

ANDREWV G. SPINNEY. CHARLES A. TWIGG. 

